The present invention relates to a motion transforming apparatus which transforms a continuous rotary motion of an input shaft into a motion of a predetermined type of an output shaft, for example, a special rotary motion such as an intermittent rotary motion or a swinging motion, or combinations of these special motions combined with each other or with a linear motion.
A motion transforming apparatus generally comprises an input shaft connected with a driving means such as a motor and an output shaft connected with a driven device such as a turn-table or a conveyor, and transforms a continuous rotary motion of the input shaft into a motion of a predetermined type as described above through a motion transmitting cam means for driving the device through the output shaft. In a motion transforming apparatus of the above-mentioned type, there is a problem that the load torque acting on the output shaft ceaselessly fluctuates throughout the operation of the apparatus and the fluctuating reaction torque of the output shaft is delivered to the input shaft as a fluctuating torque. This fluctuating torque loaded on the input shaft becomes great when the apparatus is operated in a high speed, thereby making it difficult to maintain a uniform rotation of the input shaft, and frequently causing vibrations of the apparatus and accompanying operation errors. For compensating this rather great fluctuating torque, a driving means of a large size, which necessiates a great power, or a motion transmitting cam means of a large size is required.
Japanese Patent Publication No. 60-32058 discloses a motion transforming apparatus intended to solve the above-mentioned problem of prior art. In No. 60-32058, apart from the motion transmitting cam means, there is additionally provided a torque compensating cam device, which is connected with the input shaft and adapted to rotate an inertial mass. By virtue of this arrangement, the above-mentioned fluctuating torque acting on the input shaft may be compensated by a compensating fluctuating torque applied on the input shaft by the torque compensating cam means with the inertial mass rotating. This motion transforming apparatus, however, has a disadvantage that, when the fluctuating load acting on the input shaft becomes larger, the size of the inertial mass is required to be accordingly larger, requiring also the apparatus of larger size.